Before She Knew Him by Peter Swanson (2019)
But Hen has her own history with the law, and one that doesn't make her any kind of a reliable witness. It doesn't help that the only reason she recognized the trophy as the one stolen from Dustin Miller is that during a manic episode (she has bipolar disorder) she had become obsessed with his case. So of course Matthew gets rid of the trophy and Hen can't convince anyone, including her husband Lloyd, that Matthew is a murderer.
We know by about page 12 that Matthew is a murderer, so this is no traditional crime novel. But Peter Swanson's never are. The real mystery is what Hen is going to do with the information she has, and what Matthew is going to do about the fact that she knows he's a murderer. This is all very psychological, which is exactly what I like in a crime novel.
Matthew is so interesting. His early life was completely screwed up and he is very influenced by his sadistic father. His father was horribly abusive to Matthew's mother, and the result is that Matthew only wants to kill men who harm women. It's hard to argue with that, I guess, but it's a pretty harsh sentence when the harm is defined as things like cheating on a girlfriend. Matthew's brother Richard was also influenced by their parents but in a different way. The less said about that the better.
Hen was the perfect person to have dirt on Matthew, as far as the plot goes. Because of her mental illness and how that manifested in paranoia previously, she cannot convince anyone that what she observes is true. She can see Matthew murder a person in front of her and there is still doubt about her as an eyewitness. Matthew is a beloved teacher; Hen is a mentally ill woman who suffers delusions. Who is going to be believed?
If I had to criticize anything at all about this book, it's just that I wanted more from Mira. We get her perspective at one point, a point at which she is becoming suspicious about her husband, but I would have loved more from her later. I just found the whole situation so fascinating and screwed up and there was more I wanted to know about. But if my worst criticism of a book is that I want more of it, that's the sign of a pretty good book.
If you like crime novels and haven't read Peter Swanson yet, get to it! I'm very much looking forward to seeing him in person at a conference I just signed up for. He'll be on a panel with a couple of other Massachusetts mystery/thriller authors and I can't wait hear what he has to say!